Method of rolling metal



Dec. 14, 1965 N. H. POLAKOWSKI 3,

METHOD OF ROLLING METAL Filed Nov. 13, 1962 20 Fl Ga 5 3 4; ymwwmwwflw 'fimi IN VENTOE -72 6 26 Abzalis H. PolakowskL United States Patent 3,222,907 METHOD OF ROLLING METAL Natalis H. Polakowski, 500 Kin Court, Wilmette, Ill. Filed Nov. 13, 1962, Ser. No. 238,320 4 Claims. (Cl. 72-250) The present invention relates to a method for the working of metal. In particular, the invention is directed to a technique for the hot and cold rolling of metal sheet, strip, plate, and other metal shapes.

In the hot and cold rolling of various metal products, difiiculties are often experienced as a result of edge cracking exhibited by the rolled metal. Edge cracking represents a problem which is quite significant in the rolling of hard aluminum alloys, precipitation hardenable stainless steels, hard carbon and alloy steels, and the various super end refractory alloys which include large amounts of nickel, cobalt, molybdenum, zirconium, tantalum and the like. Although edge cracking is a less severe problem in soft alloys, the rolling operation nevertheless inherently sets up stresses irrespective of the nature of the material being worked, and these stresses result in the tendency toward cracking or the formation of other undesirable characteristics in metal products.

To be more specific, it has been observed that secondary tensile stresses are developed in the unsupported edges of metal stock during a rolling operation. These tensile stresses develop spontaneously and they increase in magnitude in accordance with an increasing amount of lateral spreading of the material being rolled. The problem of edge cracking is naturally particularly acute in harder metals which exhibit lower ductility. It has been proposed that the edge cracking be controlled through the use of various combinations of roll diameters, through the use of special rolling temperatures, or by resorting to particular lubricating techniques.

The techniques employed by the prior art in attempting to control edge cracking, particularly in the harder metals, have largely proven unsatisfactory. The techniques previously employed have either failed to efficiently reduce the cracking thereby resulting in undue amounts of scrap or the techniques have proven too expensive and time consuming thereby materially detracting from the efficiency of the rolling process.

It is an object of this invention to provide a completely novel technique for the rolling of metal products whereby the tendency toward edge cracking in these products is materially reduced or completely eliminated.

It is a further object of this invention to provide a technique for the reduction of edge cracking in the rolling of metal products which is effective even when applied to relatively hard metals of low ductility and which is characterized by extreme efliciency whereby the cost and labor involved in rolling will not be increased by any significant amount.

These and other objects of this invention will appear hereinafter, and for purposes of illustration but not of limitation, specific embodiments of the invention are shown in the accompanying drawings in which:

FIGURE 1 is a cross-sectional view of an assembly adapted to be worked in accordance with the instant invention;

FIGURE 2 is a plan view illustrating the eifect of a working operation on the assembly shown in FIGURE 1;

FIGURE 3 is a side elevation illustrating the effect of a working operation on the assembly shown in FIG- URE 1;

FIGURE 4 is a cross-sectional view of an alternative assembly suitable for working in accordance with the described techniques;

FIGURE 5 is a cross-sectional view illustrating the effect of working on the assembly shown in FIGURE 4;

FIGURE 6 is a fragmentary view illustrating a contemplated modification of working rolls suitable for use in accordance with this invention; and,

FIGURE 7 is a fragmentary view of the structure shown in FIGURE 6 after initiation of a working operation.

The present invention is generally directed to a technique wherein metallic members are associated with the edges of metal stock which is to be passed through working rolls. The members situated along the edges of the stock are fed into the mill alongside the stock and are deformed simultaneously with it. These members have been found to be effective to reduce the edge cracking which characterizes previous metal working operations.

In accordance with the preferred form of this invention, metallic continuous members usually of uniform cross section are maintained along the lateral edges of sheets,

strips, or plates which are being worked in a rolling mill. The metallic members should have a thickness approximately equal to and preferably slightly greater than the thickness of the stock to be rolled. As will appear in the following illustrations, the metallic members act as dams which effectively confine the stock being rolled whereby the tendency toward edge cracking is decreased.

FIGURES 1 through 3 of the accompanying drawings illustrate work 10 which is rolled to reduce its thickness. Wire-like metallic members 12 are situated along the lateral edges of this work and these members 12 are to be maintained in this position throughout the working operation.

When the work and associated metallic members are passed between working rolls 14 and 16, a reduction in thickness will take place. It has been observed, however, that lateral spreading of the work is reduced under these conditions. Actually, the metallic members 12 are subject to lateral spreading, as shown in FIGURE 2, and accordingly, the tendency toward spreading is largely taken up by these members.

The present invention is not limited to the use of a single piece of stock in a working operation. As illustrated in FIGURE 4, a plurality of members 18 to be worked can be confined between metallic dam members 20. As shown in FIGURE 5, the product of the rolling operation consists of members 18 which have been reduced in thickness but which exhibit little or no lateral spreading. On the other hand, the dam members 20 exhibit significant spreading.

FIGURES 6 and 7 illustrate an operation wherein working rolls 22 and 24 are provided with respective grooves 26 and 28. These grooves are designed to receive dam members 39 whereby the position of these members can be maintained in an effective manner. As illustrated in FIGURE 7, lateral spreading of the members 30 will take place to a significant extent; however, the members will not be displaced laterally during the rolling operation, and. therefore, the effect in reducing spreading of the work will be assured.

The modification shown in FIGURES 6 and 7 is especially useful in rolling plate or sheet wherein coilers or other guide means are not utilized. Thus, the provision of tracking or guiding grooves in the rollers will serve to reduce sidewise movement of the work which might otherwise provide inconsistent results in the product of the rolling operation.

As explained, it has been observed that the provision of metallic members or darn means in a rolling operation reduces or eliminates lateral spreading in the work being rolled. It is believed that the results arise at least in part due to the preferential deformation of the darn means which have more freedom since they have one unconfined exposure. Because of the greater tendency toward distor- ,is contemplated since the ability of these members to reduce edge cracking Varies somewhat depending on their particular dimensional characteristics. Furthermore, in the practice of this invention, it is contemplated that relatively inexpensive metal be employed for the dam means, and this metal need not be of the same composition as the work. It will be appreciated that the results of this invention can be achieved under a wide variety of conditions and that the tendency toward edge cracking in a given met-a1 will largely govern the nature of the dam members.

As previously indicated in the preferred form of this invention, the dam members comprise wires or rods having a thickness substantially equal to or slightly greater than the work. Soft and ductile material, such as mild steel, may be utilized for the dam members since this material will readily deform, is relatively inexpensive and can be discarded when the rolling operation is completed.

It will further be understood that in addition to the alternatives above described, various other changes and l modifications may be made in the method of this inven- That which is claimed is:

1. A method for the rolling of elongate metal stock comprising the steps of providing wire-like metallic members having a thickness approximately equal to said stock, locating said members along the lateral edges of said stock, providing working rolls through which said stock and said members are adapted to pass, providing guide means defined in said working rolls for maintaining said members in position with said stock being confined therebetween, and passing said stock and said members through said working rolls whereby said stock and said members are simultaneously deformed.

2. A method in accordance with claim 1 wherein said stock comprises a single piece located between said members.

3. A method in accordance with claim 1 wherein said stock comprises a plurality of pieces arranged in side-byside relationship between said members.

4. A method in accordance with claim 1 including the steps of forming grooves in said working rolls to provide said guide means, said grooves being dimensioned to substantially fit the portion of the respective members to be received therein.

References Cited by the Examiner UNITED STATES PATENTS 281,184 7/1883 Greer -59 2,008,626 7/1935 Murakami 29--528 2,371,671 3/1945 Blount et a1. 8060 2,612,195 9/1952 Rah-aim 80- 63 XR 2,898,667 8/1959 Orehoski et a1 80-60.3 3,129,503 4/1964 Ripling 29528 3,144,712 8/1964 Ripling 29-528 WILLIAM J. STEPHENSON, Primary Examiner. 

1. A METHOD FOR THE ROLLING OF ELONGATE METAL STOCK COMPRISING THE STEPS OF PROVIDING WIRE-LIKE METALLIC MEMBERS HAVING A THICKNESS APPPROXIMATELY EQUAL TO SAID STOCK, LOCATING SAID MEMBERS ALONG THE LATERAL EDGES OF SAID STOCK, PROVIDING WORKING ROLLS THROUGH WHICH SAID STOCK AND SAID MEMBERS ARE ADAPTED TO PASS, PROVIDING GUIDE MEANS DEFINED IN SAID WORKING ROLLS FOR MAINTAINING SAID MEMBERS IN POSITION WITH SAID STOCK AND SAID MEMBERS THROUGH SAID WORKING ROLLS WHEREBY SAID STOCK AND SAID MEMBERS ARE SIMULTANEOUSLY DEFORMED. 